Enlarging hole through concrete wall - involves pressing tapered units into holes made nearby, and blowing wall sections away

摘要

One or more holes (2) are drilled, close to the passageway, in a process for increasing the size of such a passage through a wall (1) made of concrete or other hard masonry material, or for breaking the wall away. The tapered end of a conical or wedge-shaped workpiece (3) is inserted in each hole. The workpiece is pressed against the wall, and parts of the wall are then blown away, towards the original passage hole. A workpiece of this type may be inserted at both ends of each hole, and then pressed against the wall. Use can be made of a bolt (5), with one end (17) bearing the workpiece, and inserted through the hole, with its other end (18) hung into a draw device (11). A piston-and-cylinder unit can drive the workpiece against the wall. This is quick, requires min. force, and involves min. noise and dust.